Metal bending machine with jointed sweep arm carrying a mandrel



5'? 20, 3949 F. L. DUE-R METAL BENDING MACHINE WITH JOINTED SWEEP ARM CARRYING A MANDREL 4 Sheets-Sheet l Filed Sept. 7, 1946 wunvluvuw wel Jh am.

NN NUN Dec., 2U, 1949 F. L.. DUER 49L893 METAL BENDING MACHINE WITH JOINTED SWEEP ARM CARRYING A MANDREL Filed Sept. '7, 1946 4 Sheets-Sheet 2 Sw QT Il! hm, mw N.

Dec.. 2U, i949 F. L. DUER 2,491,893

METAL BENDING MACHINE WITH JOINTED swEEP ARM CARRYING A MANDREL Filed Sept. 7, 1946 4vSheets-Sheet 34 Dwz., ma. W49 F. DUER METAL BENDING MACHINE WITH JOINTED SWEEP ARM CARRYING A MANDREL 4 Sheets-Sheet 4 Filed Sept. 7, 1946 Patented Dec. 20, 1949 UNITED STATE-S PATENT OFFICE BENDINGE MACHINE WITHl JOINTED SWEEP AiRMl CARRYING Ar MANDREL Frederick L. Ducr, Chicago, Ill;

Application September 7, 1946 Serial' No. 695,436

8l' Claims.. l.

This. invention relates to improvements in metal. bending machines and has for an object to provide a machine by meansv of which tubing and like materials may be bent into predetermined angular forms.

It is an objecty of the invention to provide a metal bending machine capable o i forming` a plu.- rality of angular bends in av length of tubing or similar material without rearranging or readjusting such material on the machine preparatory to the making of individual and/or succeeding bends therein.

Another object of the. invention. residesV in the provision of, a machine of the indicated character so constructed and operable that a. plurality of predetermined angular bends (bends of predetermined degrees) can be collectively eiectedl in, a length of material.

As will be readily understood and, appreciated by skilled artisans, metal bars, rods, strips, tubes, etc. have been and are being bent into various shapes and angular relationships by bending ma chines. The indicated character of bending is effected by adjustment of the. stock to be bent to a predetermined position on a bending machine,

whereupon the machine is operated.` Then, if a second bend. is to be made in the. stock,. such., stock is repositionedor readjusted in such machine. following which the machine is operated. to eiect the second bend. This method. or procedure of operation is. repeated as many timesas are required to make the desired number of bends. in a. length of stock material.

Whereas, step-by-step bending of materials, in the manner stated, results in the ultimate production of a iinished. piece, it is a well` known fact that the labor costs associated withsuch produc.- tions are material, especially, in products having a multiplicity of angular bends therein throughout their lengths. Moreover, in production work Where a number of angular bends are formed in a length of material, considerable care and. skill on part of machine operators. is required to ensure accurate angular bends and sim.- ilar succeeding bends. Without such care. and skill by the artisan, plus the incidental time absorbing and material cost procedures, unsatisfactory `productions, more generally,` result.

Through the medium of my improved metal .lf-ending machine, the collective and individual forming of a plurality of angular bends of predetermined degree or degrees in` and throughout the lengths or bar, rod, strip, tubing, etc., stock can be made, all without the necessity of readjusting such. stock following its initial arrangement and/or engagement in. the. machine. In consequence, a material saving4 of labor and. time is eected, along with. proportionate reductions ci production costs and av materially increased rate of production. Additionally, and most im,- portant, the production` ot bent devices. made of bar, rod,I strip, tubular and` other length` materials, each an accurate and faithful replica oli the other, will., be effected.

The foregoing,A as wellI as other; objects, advantages and meritorious.- teachings` ofmy invention,4 will be in part obvious and in partv pointed out in the following detailed disclosure thereof, whenA taken in con-junction. with the accompanying drawings, it being understood that the form of the invention presented herein. is precise. and what is now considered to be the best mode of embodying its principles, but that modifications and changesmay be made in specific` embodiments without departing from its essential features.

In the drawings:

Figure 1 is a top plan view of my improved machine.

Figure 2 is a front elevation of the same with the machine bed iragmentally shown.

Figure 3 is an4 end elevation, of` the machine.

Figure 4 is a vertical transverse section taken on` the line 4 4 of Figure 1, looking in the. direction in which the arrows point,

Figure 5 is an enlarged top View of certain of the bending assemblies with another thereof'fragmentally shown, following the initial placement of a length of stock material to be bent in, the machine preparatory to its bending.

Figure 6 is a similar view in which the bending assemblies have been moved. for theY making of initial bends in a length of stock material, shown herein to be tubular.

Figure 7 is a similar View in which one of the bending assemblies for making a` succeeding bend in the length of tubular stock material` is` shown in, an operated position, and

Figure 8 is an elevation of a length. of stock material which has. been bent, in two. operations, to substantially U- shaped formation.v

Referring in detail to the drawings, my improved bending machine, generally, comprises a bed or stand I mounting a bed. plate 2 on` its upper side, on which a substantially U-shaped, support.- ing body 3 is xedly arranged adjacent one of. its ends and disposed longitudinally of the bed plate. The leg portions of the supporting body 31 as shownin Figure 4 of the drawings, are arranged indierent horizontal planes and its vertical portion has` a way or opening 3.', of appropriate shape.

and size, formed therein, as shown in Figures 1 and 4.

Bending assemblies 4 and 4 and 5 and 5 are mounted on the bed I through or by means of the supporting body 3.

The bending assemblies 4 and 4 are complemental, except, as will be seen upon reference to Figure l, they are arranged in opposed relation. Therefore, in the pertinent descriptive matter following, reierence will be made only to the assembly 4 and this will suice for the assembly 4'.

The assembly comprises a horizontally positioned bifurcated or U-shaped metal body 6 whose opposed extremities are relatively thickened adjacent their free end portions, as at 1, and formed with vertically aligned bearing openings, while its vertical basal portion has a longitudinal way 8 therein. The metal body 5, including the opposed extremities, is of angular formation (substantially dog-leg shaped). bearing openings of the thickened end portions I loosely receive therethrough a cylindrical nonrotatable post s vertically mounted in the U- shaped supporting body 3, and, as shown in Figure i of the drawings, said thickened end portions have more or less straddling engagement with the upper leg portion of said supporting body 3. Thus, it will be seen that a pivotal or swinging mounting of the bending assembly l on the bed I is eifected. If desired, non-rotatable mounting or positioning of the post 9 may be ensured by engaging a binding or locking screw 9 through an appropriate portion of the U-shaped supporting body 3 and with an adjacent portion of said post s Y(see Figure 2). A gear I is also loosely mounted on the non-rotatable post 9 immediately below the lower or adjacent end portion 1 of the bending assembly body 6, and is locked thereto by a coupling pin or key I I. The upper end of the non-rotatable post 9 is peripherally reduced at I2 and formed with a further reduced and screw-threaded extension I3, the purpose of which is hereinafter more fully described.

Opposed extensions or enlargements i4 and I5 (see Figures 5- to 7) are integral with the normally upper side of the body 6 in proximity to the point of its intermediate angling and have a stub-axle iii and a non-rotatable post Il vertically engaged therethrough. The axle IE rotatably receives a horizontally positioned thrust roller I8. A horizontal bending and forming peripherally grooved roller i9 is non-rotatably received on the reduced portion I2 of the nonvrotatable post 9, being locked thereto by a nut turned onto its screw-threaded extension I 3. In this particular connection, attention is directed to the fact that the thrust and bending and forming rollers i8 and I9 are in the same horizontal plane directly above the upper side of the body 6.

Bolted or otherwise xedly connected, as at 2i, to the opposite and outer end of the U-shaped and dog-leg angled body 6 is a cylinder 22 whose open inner end aligns and communicates with the way 8 in said body. A plunger 23 is slidably received in the cylinder 22, the rod 24 of which passes through a suitably packed gland in its head and has the free end thereof screwthreaded. A stop-sleeve 25 is movably received on the rod 24 adjacent its screw-threaded portion and is adjustably engaged by lock-nuts '2B turned thereinto. Obviously, by turning the nuts 26 the length of the stroke of the plunger 23 in the cylinder Y22, may be pre-adjusted. To the inner The side of the plunger 23 a rack-bar 21 is endwise fixedly connected, and as will be observed upon reference to Figure 1 of the drawings, said bar extends longitudinally from the plunger and its cylinder into meshed engagement with the teeth of the gear of the companionate bending assembly 5, hereinafter more fully described.

In order that controlled collective pivotal or swinging movement of the bodies of the bending assemblies d and t' may .be effected, a cylinder 28 is immovably mounted on and longitudinally of the bed plate 2, as at 2G. plunger 35i is slidably received within said cylinder. To one side of the plunger, a rod 3i is fixedly connected. This rod movably receives thereon a stop-sleeve S2 adjustably engaged by lock-nuts 33 turned onto its screw-threaded end 34. To the opposite side of the plunger 3Q within the cylinder 28, a longitudinally disposed ,rod iii is connected and the rei'nainingr or outer end of the same is engaged through the adjacent head of a subordinate cylinder 36 in which a plunger 3l' slidably works. A rod 38 is connected to the plunger 3l and extends, through a suitably packed way in its end, longitudinally therefrom. Integral with or fixed to the free end of the rod 33 is a bar 39 having rack teeth @il on its opposite sides. These rack teeth 46, as clearly shown in Figures l and 5 of the accompanying drawings, are in constant mesh with the teeth of the gears Eil of the complemental though relatively opposed bending assemblies Li and The outer and free end of the bar Se is slidable through the way 3 in the U-shaped supporting body 3, and so, is assured of predetermined and unimpeded longitudinal movement for effectually transmitting motion to the gears iii and hence to their respective bending assemblies d and li', from the cylinder received plunger 3Q.

The bending assemblies 5 and 5 provided, respectively, to the bending assemblies 4 and 4', are complementally constructed and when operatively associated with the latter, are in opposed relation (see Figure l of the drawings). Hence, for brevity, only the assembly 5 will be specically described; it being understood that such description will suihce for both thereof.

The bending assembly 5 comprises an armlike body di, suitably braced throughout its length, formed or provided with an offset and sturdy thickened bifurcated inner end portion 42. Vertically aligned bearing openings are formed in the free end portions of the upper and lower sides of the bifurcated end 42 and, as shown in Figure 2 of the drawings, said upper and lower sides have straddling engagement with the lower side of the body t of the bending assembly 4. Swingable mounting of the thus engaged bending assembly 5 on and with relation to the bending assembly i is effected by passing the nonrotatable post il from the extensions I5 on the body 6 through the aligned bearing openings of the biiurcated end 42. The non-rotatable post, if desired, may be keyed or otherwise connected to the extensions le and its upper end is extended for a suitable distance above the upper side of the body t where it non-rotatably receives a bending and forming peripherally grooved roller 43. The roller t3, as shown in Figures 2 and 3 oi" the drawings, is arranged in a horizontal piane corresponding to that of the bending and forming roller i9 of theY bending assembly il, as well as that of its thrust roller I8.

The upper side of the bifurcated end 42 of the arm-like body 4l is somewhat longer than its Alower side .and vhas ,its free end .arcuately formed and peripherally equipped or otherwise provided with gear teeth 44. 'Ihese gear -teeth 44 mesh -wlth `the teeth of the tangentially disposed grack bar f2.1.. 4In consequence, motion `.from said rack har 12], with :rectilinear movement `of 'the same, will .be transmitted to the armlike body 4I of :the bending assembly 5, causing its pivotal or .swinging movement with relation to the bending `@assembly 4 -in a predetermined `direction :and lio .aipredetermined degree or extent.

Aniintegral extension or enlargement 45 is pro- `vided ,on one edge of the upper side `or the bifureated end 42 of the body 4;I inwardly .and

laterally of its gear toothed end 44 Aand bending and forming .roller 43, and has .a suitably .sized cylinder 46 fixed to and depending from its under side. A plunger 41 is slidably received inthe cylinder and has the rod .48 thereof extended `upwandly therefrom through an aligning opening s in said extension 45 to a point thereabove where it mounts a thrust roller 49 normally disposed-in :the same horizontal plane of Ythe bending and fforming rollers I9 and 43 and the thrust roller 4:8, aforesaid.

"The length of the arm-like body4I ofthe bend- -ing assembly 5 is such that it will serve to adequately accommodate and .support a mandrel 59, A cylinder -51I is supported on and longitudinally of the outer end portion of the body 4 I (see Figures 1 and 2) and slidably receives therein a plunger 52, the rod 53 of which extends long-itudinally ofthe body, from the cylinder, and has adjustable screw-threaded connection with the adjacent end of said mandrel 50, as at 53'. A guide bracket 54, or its equivalent, is lmounted on the rinner end 4portion of the body 4I, suitably spaced from the cylinder 5 I, and suitably receives themandrel 50 and the rod 53 therethrough, `for an obvious purpose.

To limit the extent of sliding movement of the mandrel 50 and its rod 53 into a tubular body, such as designated by the reference letter T, preparatory to and/or at the time of making of a second or second operational-stage bend hin said tubular body, I preferably mount, at an appropriate point on the arm-like body 4.I a bracket plate 55, slotted at 56 for longitudinal adjustable connection to said body 'by set or 'locking screws 51. A dog 58 is pivoted to the ,intermediate portion o f the bracket plate 45 5 and. when swung inwardly with respect to the rod 5 3, will, at times, abuttingly engage with the shoulder adjacent the point of connectionof said .rod with .the plunger 52, and so, stop or limit movement of the mandrel 50 4at or .to the proper point.

At .this point, it may be noted that `suitable and .usual conduits or piping and .control valves (not shown in the .drawings becaues they ,form n o part of the invention) are supplied to the cylinders 22, 23, 36 and 46 of the bending assemblies 4.4 and 4 and 5 and 5, and to the -mandrel cylinders 5I of the bending assemblies 5 and 7,5', whereby motive power (hydraulic, pneumatic, etal may be conducted to and from the same for Aeffecting their `controlled operation.

ln operation of my bending machine, ,partieular-ly, for the bending of a tube .or tubing T,

into .a shape as shown in Figure 8 ofthe drawings,

wherein said tubing -is lformed with a plurality of angular bends to accord to it a substantial 1U.- shape y,with oDpOsitely `.disposed `'lateral ends, .the straight length lof tubing T is :placed in the ma chine :in the l:position shown `in 'Figures l and 2.

B ln .such position. :it will 'be noted that the itubing lies-with portionsthereof .adjacent-.the -peripheries .of the bending `and vforming rollers :I.9..of Z.the bending assemblies '4 and .4-' i. e.. between the same and vthe thrust rollers t8, while .outward por.- tions 4thereof are peripherally adjacent and be tween the bending and -forming rollers 43 and thrust krollers -49 of the bending assemblies f5 and 5. To :facilitate this positioning of the tubing'T in the 4machine between and adjacent said .bending and forming rollers and thrust rollers, the plunger 73i! working in the cylinder 28, is moved therein to the ylimit of its inward position, caus ing the rack bar 39 -to move with it and thusfro tate the gears I0 of the bending assemblies 4 and 4. Rotation of said gears I0 on their respective bearing posts 9 will be transmitted to the LI- shaped body 6 and the bending assemblies 4 and 4', causing each of Vthem `to be jpivotally moved or swung outwardly about or Vwith relation to their respective bearing posts 9. Further outward swinging of the bending assemblies 4 and 4 will `be effected by admitting motive fluid or like power means to the subordinate ,cylinder d6 whereby the plunger 31 slidably received ,therein will 'be thrust inwardly with respect to its .cylinder, and thus, impart a .second stage of rectilinear movement to the rack'bar .3 9. This second stage movement of `the rack bar 39 .under influence o f the subordinate cylinder 36 and its plunger 31, as explained, will transmit .further outward pivotal or swinging movement to ,the bending assemblies .4 and 4 through their respec- Y tive gears I0 and said assemblies will, thereby,

be positioned in themannershown in Figure .5 of the accompanying drawings. In .such positions, it will be observed, upon reference to said Figure 5 of the drawings, that suflcient .clearance or space will be effected between the thrust rollers .I8 and .the bending and forming rollers .I9 of the bending assemblies 4 and .4' and the rollers 43 of .the .assemblies 5 and 5' to .permit free or .unimpeded ,arrangement .o r placement of 4the tubing T in the machine and between said rollers. concurrently with such second stage movement ofthe assemblies 4 and 4 and 5 and .-5, pressure isadmitted yto the cylinders 4 6 of the assemblies 5 and 5' `whereby to effect lowering of their rods 48 ,and so, likewise lower the thrust rollers 449 of said assemblies to points :1v-here they will not interfere with placing of the 'tube T Lin the machine, i. e., into proper positioning -with relation to the rollers I8, I9 and 43. With the tubing T thus placed in the machine in 4 positidn for bending, motive means is admitted into the subordinate ylinder 36 from its opposite end v:for driving or f vzzrcing the plunger 3i outward-.15 therein, causing the rack bar v 39 to be returned to its initial position, as shown in vFigure jl, and the thrust rollers I8 and the forming rollers .43 ofthe bending assemblies 4 and 4 .and 5 and 5 to be brought into .contact or ,abutting engagement with adjacent portions of the tubing T. Thereupon, pressure is so admitted to the cylinders 46 as to cause their rods 4B to .be raised, and so, likewise raise the thrust rollers 49 of the assemblies 5 .and 5' to positions Where they will effectually thrust engage adjacent portions of the tube T.

At this time, the machine is ready for the initial bending of the tubing T. To accomplish such bending, motive means is admitted to the proper end of the cylinder "28 and in ,so doing, the plunger 35 -slidable therein, will be driven in an outward direction, `whereby to-sW-ingthe bend-I ing :assemblies 4 fand" 4 I vinvi/"ardlyftothepositions shown in Figure V6 ofthe drawingsi During-this latter emovement of the. bending Vias'sernblies'T4 and 4'-v driven vby the rack "zbar 339'I through the gears jill, it'willf'be seen thatjth'ose portions* of the tubingTv directlyl over'for adjacent the peripheral surfacesV of their bendingxand `forming rollers 19, will be bent over 'and aboutthe same. This constitutes vthe iirstfstage "of: bendingx of the tubing T, andasiwill benotedion 'reference to saidFigure 6 ofinthe drawings, the,V tubing will have a pair'of angular bends'collectively effected therein. Crushing or distortion-ofthe tubing T adjacent its points of bending over fandabout the bending and forming-rollers I9 will be prevented by engagement of the mandi-els 5i! in and through the tubing to vpoints tangential to-their respective axes. y i Y f, 1 I f j Y In instances of. production vwhere second stage bends or bending operationsara-to `be elected by the machine on the tubing T arranged-therein, the mandrels 56 are retracted ordrawnoutwardly of the angularlyv disposed rleg portions of such tubing to points substantially tangential to the axes of the bending and .forming rollers 43 of the bending assemblies 5 and 5'., Thereupon, motive power is appropriately admitted. to the cylinders 22 mounted ori-the outer,v ends of the U-shaped bodies B of-the bending assemblies 4 and 4', causingthe plungers .23 therein to-be slidinglyV moved,l together with their respective rack bars 21, in directions tov transmit rotation to the bending assemblies 5 and5 in directions whereby said bending assemblies 5 and 5' will be swung from the position shownV in Figure 6 to the position shown in Figure 7 ofthe accompanying drawings; This collectivepivotal movement of the bending assemblies 5 and 5'under influence of power and motion imparted thereto from the operated rack bars 2",V will effect angular bending ci those portions of the tubing T adjacent and engaged withthe peripheral surfaces of the bending and forming rollers 43 over and about the same, as shown in Figure k7.,

` Obviously, the orbital paths `of movement of the thrust rollers i8 and 49, duringtheir respective periods of operation, will anchor,n the adjacent and engaged portions of the tubing 'T against relative movement, and so, ensure effectual and satisfactory bending of it about those portions adjacent and engaged with their respective bending and forming rollers I9 and 43.

To remove the multi-stage bent tubing T from' the machine, motive power is collectively'or otherwise suitably admitted to the cylinders 46 carried on thefbending assemblies Aand 5 supporting the thrust rollers 49. The motive power is so admitted as to cause the plungers 4'! working in said cylinders to be forced vdownwardly therein. During such movement of the plungers along with their respective rods SilJ it will be seen that the thrust rollers 49 carried on the upper ends of said rods, will be dropped or moved downwardly to points below adjacent portions of the bent tubing T. Atl this time, motive power is appropriately admitted to the cylinder 23 to cause rectilinear movement of the rack barI .39 in a direction opposite to that first explained. Thereby, said rack bar 38, meshing with Vthe gears i0 l carried -with Vthe same. --The bentI tubingtmay now be readily removed from the machine; 1 y The bending assemblies 5 and 5 are, ofcourse, returned to their normal or initial position by reversing 'operation of their respective driving rack bars 21 of the cylinders and plungers 22 and 23, respectively. i

By adjustment of the stop-sleeves 25 and\32 longitudinally of their respective plunger rods 24 and 3l, through appropriate turning of the lock nuts 2e and V33, it will be seen that the lengths of the working strokes ofA the cylinder plungers 23 and 30, may be regulatedas' required or desired, and therefore, that the extent' of movement of the rack bars 2l and 39 may be regulated to eiect pivotal or swinging movement of the bending assemblies 4 and 4', and 5 and 5. to a minute degree.Vv In Athis manner, thean.- gularity or. the degree of bends eiected in tub.- ing or other lengths of stock arranged inV themachine may be adjusted or varied, such as operating conditions or preference may dictate. Moreover, by so controlling the length of the working strokes of the cylinder provided plungers 23 and 36, it will be understood that succeeding bends made in tubing or other lengthsA of stock successively placed in the bending machine will be accurately and faithfully reproduced, i. e., one will be a faithful and true replica of the other.

Whereas, I have hereinbefore" described.v with some degree of particu1arity,'the improved bending machine as being used v-for the bending of lengths of tubing, it will be understood andap'- preciated by workers skilled in the art, that various forms of materials may be effectually and satisfactorily bent thereby, as for example, bars, rods, strips, etc., of metal and other materials.

I claim:

1. A bending machine, comprisinga supporting bed, an arm swingably mounted-on the bed, gear teeth on and about that. portion of Vsaid arm swingably mounted on said bed, a bending and forming means liXedly mounted adjacent the arm in proximity to its point of pivotal mounting on said bed, a thrust means on the arm longitudinally and transversely spaced from said bending and forming means, a second arm swingably mounted on the outer and free end portion of said first mentioned arm beyond the bending and forming means and the thrust means on said rst mentioned arm, gear teeth on and about the pivotally mounted end portion of said second arm, a bending and forming means xedly mounted on said second arm in proximity to the point of its pivotal mounting on said first mentioned arm, a thrust means on the second arm longitudinally and transversely spaced from said second mentioned bending and forming means, a rack bar slidably mounted on the bed meshing with the gear teeth on said rst mentioned arm for transmitting swinging motion to the same, and Va rack bar slidably mounted on a portion of said iirst mentioned arm meshing with the gear teeth on said second arm for transmitting swinging motion thereto.

2. A bending machine, comprising a supporting bed, an arm swingably mounted on the bed, a. bending and forming means on the arm, a thrust means on the arm longitudinally and transversely spaced from said bending and forming means, YaV second arm swingably mounted on the iirst meri--n tioned arm beyond the bending and forming means and thrust means Von said first mentioned arm, a. bending and forming means on said second arma, thrust means on the second.;arm

d longitudinally and transversely spaced from said `second mentioned bending and `forming means, means for `selectively imparting controllable pivotal motion to each of said arms, and a longitudinally adjustable mandrel mounted on said second arm adjustably (movable longitudinally inwardly and outwardly with relation thereto and with relation to said iirst mentioned arm.

3. A bending machine, comprising a supporting bed, an arm swingably mounted on the bed, g'ear teeth on and about the swingably mounted end portion of said arm, a' bending and `forming means fixedly mounted adjacent the arm in proximity to its point of pivotal mounting on said bed and said gear teeth, a thrust means on the arm longitudinally and transversely spaced from said bending and forming means, a second arm swingably mounted on the first mentioned arm at a point beyond the bending and forming means and the thrust means cn said iirst mentioned arm, gear teeth on and about the pivctally mounted end portion of said second arm, a bending and forming means iixedly mounted on said second arm in proximity to its point of swingable mounting on said rst mentioned arm and to the gear teeth on the swingably mounted end portion of said second arm, a thrust means on the second arm longitudinally and transversely spaced from said second mentioned bending and forming means, a rack bar slidably mounted on said bed meshing with the gear teeth on said first mentioned arm, a second rack bar slidably mounted on said first mentioned arm meshing with the gear teeth on said second arm, and means on each of said rack bars for controlling the extents of their respective inward sliding movement.

4. A bending machine, comprising a supporting bed, a horizontal arm swingably mounted at one of its end on said bed, gear teeth on and about the pivotally mounted end of said arm, a bending and forming means xedly mounted on the arm in proximity to and concentrically of its pivotal mounting on said bed, a thrust means on the arm longitudinally and transversely spaced from the bending and forming means, a second horizontal arm swingably mounted at one of its ends on a portion of said first mentioned arm beyond the bending and forming means and the thrust means on said first mentioned arm, gear teeth on and about the pivotally mounted end portion of said second arm, a bending and forming means xedly mounted on the second arm in proximity to its point of pivotal mounting on said iirst mentioned arm and concentrically of the same and the gear teeth on said second arm, a thrust means on the second arm longitudinally and transversely spaced from said second mentioned bending and forming means, a rack bar slidably mounted on said bed meshing with the gear teeth on said rst mentioned arm, a cylinder on the bed outwardly of said rack bar, a plunger slidable in said cylinder connected to said rack bar, a rod extending from said plunger through the outer end of said cylinder, a cylinder mounted on a portion of said first mentioned arm, a plunger slidable in said cylinder, a rack bar connected to said plunger without said cylinder meshing with the gear teeth on said second arm, a rod connected to the plunger of the second mentioned cylinder extending through and from the outer end of the cylinder, and adjustable means on each of said rods for limiting the extent of movement of the respective plungers to which they are connected.

5. A bending machine, comprising a supporting bed, bending and forming means swingably mounted on the supporting bed, other bending and forming means swingably mounted with relation to the iirst bending and forming means, means for transmitting swinging motion to the first and second bending and forming means, an adjustable mandrel slidably mounted on `one of said bending and forming means selectively adjustable to predetermined positions with relation to either one of said rst or second bending and forming means and means engageable with said mandrel for releasably though iixedly retaining the mandrel in a selectively adjusted position with relation to either said first or second bending and forming means.

6. A bending machine, comprising a supporting bed, an arm swingably mounted on the bed, a bending and forming means xedly mounted on the arm, a second arm swingably mounted on a free outer portion of the rst mentioned arm beyond the bending and forming means on said first arm, a bending and forming means iixcdly mounted on said second arm spaced from the bending and forming means on said iirst arm, thrust means on the second arm spaced from the bending and forming means on said second arm, meansfor selectively transmitting predetermined swinging motion to each of said arms, and an adjustable mandrel movably mounted on the second arm, said mandrel being selectively adjustable to predetermined positions with relation, to either one of the bending and forming means on said first or second arms.

7. A bending machine, comprising a supporting bed, an arm swingably mounted on the bed, gear teeth on a portion of said arm in proximity to its pivotal mounting on the bed, bending and forming means nxedly mounted adjacent the arm in proximity to its point of pivotal mounting on the bed, a second arm swingably mounted on a portion of said first arm beyond its pivotal mounting and beyond the bending and forming means thereon, gear teeth on a portion of said second arm in proximity to its pivotal mounting, a bending and forming means fixedly mounted on said second arm in proximity to its point of pivotal mounting on the first mentioned arm. and thrust means on the second arm spaced from said second mentioned bending and forming means, a rack bar slidably mounted on the bed meshing with the gear teeth on the rst mentioned arm for transmittingr swinging mction thereto, and a rack bar slidably mounted on a portion of said first mentioned arm, meshing with the gear teeth on said second mentioned arm for transmitting swinging motion thereto.

8. A bending machine, comprising a supporting bed, an arm swingably mounted on the bed, a bending and forming means xedly mounted on the bed adjacent said arm at its point of swingable mounting on the bed, a second arm swingably mounted on a portion of said iirst arm beyond its swingable mounting and beyond said bending and forming means, a second` hending and forming means iixedly mounted on the second arm, means for selectively transmitting predetermined swinging motion to each of said arms, and an adjustable mandrel slidably mounted on the second arm, said mandrel being selectively adjustable to predetermined positions with relation to either one of the bending and forming means on said iirst and second arms.

FREDERICK L. DUER.

(References on following page) REFERENCES CITED Iumbel 1,667,911 The following references are of record in the 2.357 873 le of this patent:

UNITED STATES PATENTS 5 Number Number Name Date 171,560 785,082 Brinkman Mar. 21, 1905 347,942 898,424 Bartlett Sept. 15, 1908 543,019 957,200 Gail May 10, 1910 10 240,590 1,066,247 Brown July 1, 1913 517,373 1,379,858 Gail May 31, 1921 60,774

Name Date Van Veen May 1, 1928 Bower Sept. 12, 1944 FOREIGN PATENTS Country Date Great Britain Nov. 24, 1921 Great Britain May 7, 1931 France May 24, 1922 Germany Nov. 7, 1911 Germany Feb. 2, 1931 Norway Apr. 24, v1939 

